Topic: Shift mechanism

[lash]

Is it possible to use a shifter assembly from a later ,72-74, in a 69 engine?

[Don R]

 I believe so, the shift drum and maybe shift forks were improved from the early bikes, but I think the ratchet part stayed the same. Take photos unless you have another one to look at.

[69cb750]

Yes, three times, neutral stop much better.

[HondaMan]

If it is not a sandcast engine,the later parts will fit. Some early K0 engines also have the sandcast-style shifter drum, too, so the Neutral Detent Arm is different in those early ones, and their drums.

[lash]

Engine is 1013953 so it sounds like it would work.
Also, anyone know what the thread is for the inside of the drive sprocket? I want to block off the chain oiler.

[HondaMan]

Engine is 1013953 so it sounds like it would work.
Also, anyone know what the thread is for the inside of the drive sprocket? I want to block off the chain oiler.

That trick isn't as easy as it seems: I just did it with a sandcast engine. My first suggestion would be to just turn the existing oiler adjuster screw in until it stops: this normally seals off the oiling passage by using the plate and seal that is inside the countershaft - it was made to do that. There is also one (or two) holes in the sides of the countershaft for that oil to weep out onto the surface of the sprocket: you can clean them well and poke some JB Weld inside them for a permanent closure.

If the cases are open, you can just remove the oiler collection pan at the back of the countershaft.

If you wish to do it the other way: the thread inside is can be matched up to a bolt at your local Ace Hardware, but you will find it is not a standard length. I had to custom-trim off the end of a new bolt and then grind off the inner 2 threads to make a plug, as the hole is tapered before it hits the screen inside the countershaft, and the taper has no threads back in there. The taper ends [(right at the edge of the oiler holes) + (1 more thread)], so it only closes off the hole by 1 thread. A final caution: the 'stop' inside the countershaft is a screen. When you feel resistance at the end, don't tighten the bolt against it: instead, shorten the bolt. If you break the screen off inside the shaft it can end up floating around in the crankcase.

But...why do you want to kill the oiler completely? The chain needs it: in 1970 this bike earned the official street nickname of "The $1695 chain breaker" (that was its retail price then). Just askin'....

[newday777]

Engine is 1013953 so it sounds like it would work.
Also, anyone know what the thread is for the inside of the drive sprocket? I want to block off the chain oiler.

http://forums.sohc4.net/index.php/topic,115121.0.html


Threads are
14mmx1.25

[lash]

I don’t have an oil adjuster screw for this engine so I have to put something in there to close the hole. I also did not install the collection pan so there shouldn’t be that much coming out.

[newday777]

Did you read through the link I posted??

[lash]

Read the whole article. I have found a bolt to fit 12x1.25 and cut to fit.

[newday777]

Read the whole article. I have found a bolt to fit 12x1.25 and cut to fit.

12mm? Not 14mm?

[lash]

12x1.25 I think 14mm was maybe later versions?

[HondaMan]

Yep, later ones are 14mm.

[newday777]

Yep, later ones are 14mm.

Ah. OK.
When was the change.

[HondaMan]

Yep, later ones are 14mm.

Ah. OK.
When was the change.

I'm not real sure: I have 5 boxes of old trannys from various engines, and some are 12, some are 14mm. I didn't label the boxes (partly because they were sent to me by others), so I don't know for sure when it happened. I do know that the final-drive shafts will swap OK, so long as the correct-width outer bearing is employed (there were 4 of those - and the sandcast's was grooved!). I replaced one in a K0 (late) engine when its OEM one was torn up by a breaking chain, and the holes were different - that's when I had to go find a correct oiler because the 'new' used one didn't have the parts in it and the K0 parts didn't fit.

[newday777]

I know the K4 and K5 are the same as my K5 oiler seal was toast, pulled the one from a K4 I have and it fit.
I haven't pulled the bolt from the K6(no oiler) yet to see if it fits.
I guess I need to check the late K0 motor I have also.

[newday777]

So going down to the shop(75' walk now!!)
My K0 has the solid bolt-no oiler adjustment shaft, so I researched CMS and the change from 12mm bolt to 14mm thread adjustable oiler appears to be at serial 1026144, mid K2 motor.

[MauiK3]

I think modern chain with modern spray on lube works well for most cases. Extreme riding not so much

[HondaMan]

So going down to the shop(75' walk now!!)
My K0 has the solid bolt-no oiler adjustment shaft, so I researched CMS and the change from 12mm bolt to 14mm thread adjustable oiler appears to be at serial 1026144, mid K2 motor.

I did that, too, then took apart a damaged K4 engine and found the 12mm bolt with the adjustable oiler in it.    (Can't vouch for originality in that one, tho..)
Then there's my own K2, which came with a K1 engine brand new, but has the 14mm hole in the final-drive shaft.    I only discovered that a few years ago when I ordered a new rubber insert for mine because it was still drooling too much when fully closed, and had to re-order the 14mm version. I still have that 12mm version in my 'spares' parts - it didn't fit the last sandcast, either... come to think of it, this is how I've ended up with a LOT of spare 750 bits and pieces like that.

I've also found the oiler-equipped final-drive sprocket in an early K6, followed by another K6 (that same summer) that had the 14mm bolt solid plug in it - which I discovered when I took the bike to the carwash (sprocket cover removed) to clean it up for an engine removal. That bolt-equipped one had no oiler pan inside, either - much like the K7 cases.

Granted, in the K6 series they were using whatever they could get their hands on to build one: that bike was a "scramble" for Honda to create in response to American Honda's roaring demand for 4-pipers again when the F0/1 sales fell flat by over 40%+ (we kept hearing "Can you put 4 pipes on it?"). At least this did result in the best paint of the series being applied to the K6 bikes, IMHO.